Sicily has issued an orange tsunami alert after 12 earthquakes struck the Mediterranean off Palermo on Friday. Officials urgently evacuated schools and government buildings. Seismologists say all the tremors had a magnitude above 3.0.

The main quake hit at 10.19am local time, less than 100km from Palermo. Early reports put it at 5 on the Richter scale, while the US Geological Survey (USGS) measured it at magnitude 5.7 at a depth of 10km.

Schools in Palermo and Messina are closed. Officials also shut other public buildings, including the courthouse in Trapani on Sicily's west coast. On the island of Lipari, between Sicily and mainland Italy, all public buildings were evacuated.

The tremors were felt in Palermo, Patti, Licata, Capo d'Orlando and Campofelice di Roccella. Palermo is the capital of Sicily and has 648,260 residents. Officials urged people to stay away from the coast and follow official instructions.

Palermo mayor Roberto Lagalla said officials are watching the situation closely. In a statement, he said there were no reports of damage or casualties, and that the authorities must do everything to keep people safe. "The possible evacuation of some public buildings is purely a precaution, driven by the need to act quickly and carefully," Lagalla wrote.